How to do the disassembly, repair and maintenance of the screw nozzle of the injection molding machine

The plasticizing device of the injection molding machine is generally equipped with an integral rotating mechanism. When assembling and disassembling the screw nozzle, screw and barrel of the injection molding machine, the positioning screw of the injection seat should first be loosened to deflect it to a certain angle from the original position, so that the axis of the injection seat barrel avoids the axis of the clamping device to facilitate the screw barrel for plastic injection mold machine. Disassembly, assembly and maintenance of screw and barrel.

a. Disassembly of the screw nozzle of the injection molding machine

If there is leftover material in the barrel, it should be heated to the plasticizing temperature first. Use polyolefin resin with high thermal stability or special cleaning material for the barrel to fully carry out high-speed cleaning, and try to discharge the remaining molten material before it can be disassembled. Work, because the residual material in the nozzle part is always impossible to discharge completely, so the nozzle or the barrel head should be heated before disassembling the nozzle.

After the screw nozzle of the injection molding machine heats up, tap it with a special hammer to loosen it. The bolts should not be loosened completely. Tap lightly when it is loosened to 2/3. After the internal gas is released, remove the nozzle.

The inside of the screw nozzle of the injection molding machine should be cleaned while it is hot at a high temperature, so that the residual melt in the runner can be taken out from the nozzle hole. The method is to inject the mold release agent from the nozzle into the interior, that is, drip the mold release agent from the side of the nozzle thread to the material and the inner wall surface, so that the material is separated from the inner wall, and the material is taken out from the nozzle.

b. Maintenance and repair of the screw nozzle of the injection molding machine: If the contact part of the nozzle and the mold positioning sleeve is in single-sided contact or poor contact during production, the front end spherical R part will be deformed, forming a groove for melt escape, resulting in overflow at the nozzle In addition, the caliber part will also be deformed, so if the overflow occurs, it should be checked and repaired in time.

c. The integrity of the threaded part of the nozzle and the sealing surface on one side of the barrel should be checked regularly. If serious wear or corrosion is found, it should be replaced in time. (Screw and barrel of injection molding machine)

d. Check the internal passage of the screw nozzle of the injection molding machine. The surface quality of the injected molten material can be observed by the air injection molding, and the residual molten material discharged from the nozzle can more accurately reproduce the flow channel condition in the nozzle. From this, the residual amount and temperature distribution of the molten material in the nozzle can be analyzed.